The study of the clonal architecture of NPM1-mut AMLs at a single cell level showed that these leukemias are usually organized following simple clonal architectures with one to six subclones and branching; in all cases studied, NPM1 mutations were secondary or subclonal to other driver mutations; in a part of these leukemias, it was postulated, through the analysis of single CD34+/CCD33− cells, the existence of pre-leukemic cells bearing one or more driver mutations, lacking NPM1 mutations [28]. Here, NPM1 is linked to leukemia.